The invention relates to a fluorescent lamp with discharge electrodes at both of its ends, and more particularly to a flat type fluorescent lamp which is rectangular in overall shape and which is formed by connecting rectangular dish-shaped halves.
The fluorescent lamp of the prior art is, in general, constructed in such a manner that it has discharge electrodes at both its ends, irrespective of the shape of the lamp. Voltage supply terminals are mounted on the stems which have exhaust pipes for facilitating the mounting of these electrodes. After a discharge electrode is connected between the terminals of each stem, a stem is mounted to each end of the fluorescent lamp. Therefore, the fluorescent lamp has a stem and voltage supply terminals projecting from each of its ends. Since a base is connected to the ends, it is necessary that the terminals for mounting the sockets project from both ends of the fluorescent lamp.
When such a fluorescent lamp serves as a projecting type display lamp used in corridors and so on, the sockets must be formed on the wall side and on the passage side. Even if a socket mounting frame is used, it is frequently the case that the base is exposed or the frame of the socket mounting portion is extremely wide at the passage side. Thus, the appearance will not be very attractive. Further, since the fluorescent lamp is a bayonet socket type, the mounting condition is unstable unless a spring biasing force is exerted on the socket toward the lamp. Thus, the lamp has the disadvantage of requiring a more complicated construction for providing the spring biasing force; further, the construction of the frame itself is complicated, and the number of manufacturing processes increases, resulting in higher cost.
The present invention was made to overcome these defects, and a major object of the invention is to provide a flat type fluorescent lamp in which the voltage supply terminals are provided at only one end of the lamp.
Another object of the invention is to provide a fluorescent lamp suitable for use as a projecting type display lamp of the kind used in corridors and so on.